Marine Weather and TidesSkidaway Island, GA

Version 3.4

What's New / NOTES
3/3/2018 - There is a new GOES Satellite for the east coast that required rewriting that part of the code. Please report any issues.
6/25/2017 - NOAA is having a major issue that impact the 7 day forecast load times. Many users are reporting problems. The issue has been reported.
5/23/2017 - Worked with NOAA again to speed up the 7 day forecast load times. Thanks to them for being responsive.

Sunrise 7:26AM

Sunset 7:36PM

Monday March 19, 2018 10:21 PM EDT (02:21 UTC)

Moonrise 7:58AM

Moonset 8:51PM

Illumination 11%

NOTE: Some of the data on this page has not been verified and should be used with that in mind. It may and occasionally will, be wrong. The tide reports are by xtide and are NOT FOR NAVIGATION.

AMZ300 953 Pm Edt Mon Mar 19 2018 Synopsis for the coastal waters of south coastal south carolina and north coastal georgia.. A warm front will move north of our area tonight while a strong cold front approaches from the west. The strong cold front will cross the area Tuesday, followed by cooler high pressure for the latter half of the week. A cold front could impact the area next weekend.

Synopsis
A warm front will move north of our area tonight while a strong
cold front approaches from the west. The strong cold front will
cross the area Tuesday, followed by cooler high pressure for
the latter half of the week. A cold front could impact the area
next weekend.

Near term until 6 am Tuesday morning
As of 945 pm: latest SPC analysis continued to show a weakly
unstable environment across the forecast area, especially across
the sc lowcountry. 0z chs observed sounding showed less than
200 j kg of CAPE and around 40 j kg of cin. Based on radar
trends and the latest hrrr run, I will expect the coverage of
the rainfall over the southern tier of the CWA to decrease
sharply by midnight. I will update the forecast to adjust pop
timing and placement through early Tuesday morning.

As of 745 pm: kclx radar indicated stratiform rain with embedded
showers thunderstorms advancing across SE ga. Latest spc
mesoscale analysis indicated that the storms have encountered
the stable air mass that was left over from the morning in-situ
wedge. I will update the forecast to increase pops across the ga
zones through 11 pm. The next interesting feature is a
developing severe MCS over northern al. This feature will likely
remain highly organize as it tracks SE across ga late this
evening into the early morning hours. However, the activity
currently over SE ga will likely work over the environment over
se ga. Steady sse winds may advect weak instability across the
sc lowcountry, but model guidance show only minor increases in
cape. Overall, this line will weaken as it approaches the
forecast area after 3 am. However, due to the rapid motion and
high organization, this line will need to be monitored closely
for severe weather.

The most interesting period for severe weather appears to occur
after sunrise Tuesday into the early afternoon. The low level
water vapor channel from goes-16 indicated what appeared to be
an elevated mixed layer over the western gulf of mexico, sourced
from the high mexican hill country. In fact, 0z sounding from
brownsville, tx indicated a layer of steep lapse rates from
600mb to 400 mb. The GFS indicates that this region of steep
lapse rates will slide east ahead of an amplifying h5 trough,
reaching the forecast area by late Tuesday morning. At the sfc,
the cold front will like sweep over the coastal plain during the
mid morning. Given a few hours of sunlight, the atmosphere will
likely become moderately unstable with significant veering llvl
wind fields. Model sounding parameters appear very respectable,
tt in the mid 50s, EHI above 1.5, sweat above 400, and wbz
around 10 kft. These storms will be in a favorable environment
for severe hail, damaging winds, and possibly a tornado.

Previous discussion:
a complex weather forecast for tonight. The
mid upper levels consist of semi-zonal flow over the area while
a stronger disturbance passes well to our northwest. There are
weaker disturbances within the general flow that will pass over
our area, but the strongest ones will remain to our north and
west. At the surface, observations indicate a weak diffuse warm
front spread across our area and slowly moving northward. It's
exact location is somewhat difficult to pinpoint, but the
expected trend is for it to strengthen and accelerate northward
this evening, being well north of our area overnight. This is
because low pressure currently moving over the lower mid ms
valley will move northeastward and intensify, becoming located
over nc by daybreak. Attached to the low will be a strong cold
front that will quickly zoom eastward. The front is expected to
be well to our west late tonight. There is plenty of moisture
across the region, with a band of ~1.5" pwats spreading into our
area from the south this evening. A disturbance is helping to
generate convection over fl. Both synoptic models and the cams
indicate this feature moving northward and into at least our
southern portion of the area this evening. It should then weaken
as it moves northward and offshore. We tried to account for it
the best we can with the hourly pop grids. But more adjustments
will be needed based on radar trends. Additionally, convection
currently near the al ga border is stronger than expected and
racing eastward. The cams haven't done that well accounting for
this, but the current thinking is for it to weaken as it gets
closer to our area and merges with the previously munitioned
weakening area of convection. Instability for our area this
evening is decent. Li's and showalter values are negative. Lapse
rates are steepening. SPC mesoscale analysis indicates mlcapes
across ga approaching 500 j kg. 0-6 km shear is 60-70 kt. So
there is the risk for strong thunderstorms with gusty winds. The
severe risk this evening is low because the best instability
remains out of our area. After this band of convection moves
through late this evening, all models are in good agreement of
their being a lull in precipitation until around daybreak. A
strong line of showers and thunderstorms will be approaching
from the west at that time. (see the discussion below for more
details.) lows will range from the upper 50s to the lower 60s.

Short term 6 am Tuesday morning through Thursday
Tuesday: an "enhanced risk" of severe weather is forecast across
parts of southeast south carolina and southeast georgia Tuesday
morning into early Tuesday afternoon, especially along the
coastal corridor.

Latest guidance indicates a progressive shortwave trough with a
strong mid-lvl speed MAX skirting along the northern coast of the
gulf of mexico and over northern florida during the day. At the sfc,
the area will be warm sectored ahead of a cold front that quickly
pushes eastward given strong and deep westerly flow off the sfc. The
timing of this front will play a large role in the overall strength
of thunderstorms and the severe weather threat across the area
Tuesday morning into early Tuesday afternoon. Given strong
unidirectional wind fields associated with the passing system along
with dcape values as high as 800-1000 j kg within the warm sector,
the main severe weather threat should come in the form of damaging
straight-line winds associated with a line of strong to potentially
severe thunderstorms during morning hours, potentially into early
afternoon.

Increasing mid-lvl lapse rates around 7-8 c km, lifted index values
upwards to -5 -6 c, along with 0-6km bulk shear of 50-60 kt could
produce bouts of moderate size hail in deepest convection. Although
low-lvl lapse rates and veering are not particularly strong over the
area (stronger north near the passing low pressure center), a quick
punch of low-lvl moisture characterized by pwats near 1.25-1.5
inches, low lcls, increasing SBCAPE (1500-2000 j kg), including a
fairly large amount of 0-3km cape, could be sufficient to support an
isolated tornado or two across the area, mainly in thunderstorms
that initially develop within breaks of a convective line or just
ahead of the convective line. The greatest potential for severe
weather is anticipated along the coastal corridor of southeast
georgia and southeast south carolina where warming into the low mid
70s coincides with the arrival of stronger wind fields and forcing
associated with the advancing cold front, progressive h5 shortwave
and divergence with a passing h25 jet aloft. Although conditions
appear conducive for strong and or severe thunderstorms Tuesday
morning and potentially into Tuesday afternoon, ongoing convection
upstream could make way into the area late tonight and impact the
overall severe weather setup across southeast south carolina and
southeast georgia. Should this scenario unfold, activity would
likely suppress the overall strength potential of thunderstorms
Tuesday morning due to ongoing rains and widespread clouds. Activity
will have to be monitored tonight for any potential changes. Once
the cold front pushes through the area, the threat of severe weather
will come to an end. However, some lingering showers are possible
into mid late afternoon hours until the mid upper lvl trough shift
offshore. Expect conditions to dry out fairly quick Tuesday night
with lows dipping into the low mid 40s.

Wednesday and Thursday: sfc low pressure will pull away to the
northeast while a mid upper lvl trough remains overhead into
midweek. The main issue will be gusty winds over much of the area as
a tight pressure gradient occurs over the southeast. In general, we
could see west-northwest wind gusts upwards to 25-30 mph as sfc
temps warm into the upper 50s lower 60s Wednesday afternoon.

Overnight lows could approach the mid upper 30s, leading to some
frost concerns away from the coast late. By Thursday, the pressure
gradient will relax with weather conditions remaining quiet and dry.

Afternoon temps should warm a few degrees, peaking in the lower
60s.

Long term Thursday night through Monday
Models remain in fairly good agreement through the long term period.

Surface high pressure will drift overhead on Friday and then
eventually into the atlantic by Saturday. A cold front will approach
from the west on Saturday, and then cross the area sometime late
weekend. Moisture doesn't appear overly impressive so little, if
any, precipitation is expected to accompany it. Temperatures will
gradually warm through the period as flow turns more southerly.

Aviation 02z Tuesday through Saturday
As of 2335z: kclx doppler radar indicated stratiform rain with
embedded showers and thunderstorms moving ene across SE ga. This
activity is expected to pass over ksav through 4z, highlighted
with a tempo from 0z-4z. By late this evening, convection should
slide off the coast and MVFR to ifr stratus should develop
across the region. A MCS developing over northern al will
organize and race SE late tonight. Hrrr times the line passing
across kchs between 10z to 14z, highlighted with a tempo. A few
cams indicate that a second round of thunderstorms may develop
during the late morning to early afternoon hours, between the
cold front and the coast. These thunderstorms will likely
develop in an environment that would support large hail,
frequent cloud to ground lightning, and damaging wind gusts. I
will highlight with a prob30 from 16z until 21z. Late afternoon
should feature gusty SW winds andVFR conditions.

Clearing will take place Wednesday, withVFR expected the rest of
the week. Breezy conditions likely Tuesday and Wednesday.

Marine
Tonight: a warm front will move north of our area while a
strong cold front approaches from the west. Winds will gradually veer
to the SW and increase, most noticeably late in the time
period. Wind gusts could approach 25 kt for the outer ga waters
(amz374), but we think they will stay just under small craft
advisory criteria. Additionally, the risk of thunderstorms
continues. Some storms could become strong enough to require
warnings. There is even a small risk for isolated waterspouts.

Tuesday through Saturday: marine conditions will deteriorate on
Tuesday as the pressure gradient tightens ahead of an area of low
pressure. A strong cold front associated with this low pressure
system will then shift offshore later Tuesday with strong cold air
advection in its wake. Small craft advisories will likely be needed,
beginning as early as late Tuesday morning in the outer georgia
waters, and then spreading to most, if not all, waters later in the
day. Gale force winds are also possible in offshore georgia waters
for a period of time Tuesday night through Wednesday morning. It's
still too early to hoist a gale watch at this time based on the
timing of the event. Winds and seas will improve on Thursday as high
pressure builds in and the gradient slackens. The high will drift
overhead Friday and then into the atlantic by Saturday, allowing
winds to become southerly.

Chs watches warnings advisories
Ga... None.

Sc... None.

Marine... None.

Near term... Ned
short term...

long term... Ect
aviation... Ned
marine...

Weather Reporting Stations

EDIT(on/off) &nbspHelpNOTE: Click on distance to see the station location on a map

Wind Forecast for Charleston, SC (22,6,7,8)

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